BACKGROUND INFORMATION
1. Field:
[0001] The present disclosure generally relates to production of composite structures, and
deals more particularly with a method and seals for sealing the edges of a caul over
a part layup on a tool.
2. Background:
[0002] Cauls are sometimes placed on a composite part layup in preparation for vacuum bag
compaction and curing in order to achieve a desired part finish and/or to evenly apply
compaction pressure over part. A flexible vacuum bag is placed over the caul and is
sealed around its periphery to an underlying cure tool using a sealant tape. The process
of draping the vacuum bag over a caul on a part layup and sealing the periphery of
the bag to the tool can be a time-consuming process, particularly where the part is
large-scale, such as the composite aircraft fuselage, or a fuselage section or a panel.
Following curing of the part, either using autoclave or out-of-autoclave processes,
the bag and sealant tape are removed and discarded. The bag material and sealing tape
are thus consumable items that increase production costs, including cost for materials
and manpower needed for vacuum bagging and sealing the bag to the mandrel.
[0003] It would therefore be desirable to be able to more easily and quickly cover a part
layup and form a vacuum tight seal over a mandrel.
[0004] The abstract of
EP 2939819A2 states 'A method for manufacturing pieces of composite material by vacuum-bagging,
wherein a laminate of uncured plies of composite material is layered up on a molding
surface, and the upper surface of the laminate is then covered with one or more caul
plates to assure smoothness of the outer surface of the final piece. According to
the invention, local vacuum bags are provided in the form of elongated strips or bands
to locally seal the edges of the caul plates such as the area of the local vacuum
bags is smaller than the area of any of the caul plates. Due to the use of local vacuum
bags, the amount of the material used is significantly reduced, thus, production times
and manufacturing cost are significantly reduced.
SUMMARY
[0005] The disclosure relates in general to processes and equipment for manufacturing composite
structure, and more specifically to methods and equipment for sealing a caul over
a composite part layup on a tool.
[0006] According to one aspect, an apparatus is provided for sealing a caul over a composite
part layup on a tool. The apparatus includes an edge seal extending around a perimeter
of the caul and configured to form a substantially vacuum tight seal between the caul
and the tool.
[0007] According to another aspect, an apparatus is provided for sealing the least first
and second cauls over a composite barrel part layout on a mandrel. The apparatus includes
a first edge seal and a second edge seal. The first caul seal extends around the perimeter
of the first caul and is configured to form a vacuum tight seal between the first
caul and the mandrel. The second edge seal extends around the perimeter of the second
caul, and is configured to form a vacuum tight seal between the second caul and the
mandrel. The first and second caul seals overlap each other and are configured to
form a vacuum tight seal between the first and second cauls.
[0008] According to still another aspect, a method is provided of making at least a section
of a composite barrel. The method includes forming a composite barrel part layup on
the mandrel, placing at least a first caul on the composite part layup, and forming
a vacuum tight seal between the first caul and the mandrel, including sealing a perimeter
of the first caul to the mandrel.
[0009] One of the advantages of the disclosed embodiments is that consumables such as large
vacuum bags and sealant tape are reduced or eliminated, thus reducing production costs.
Another advantage is that materials required to form a vacuum tight seal between a
caul placed over a part layup and a tool are integrated into the caul, allowing the
caul to be installed and sealed over the part layup more quickly. Another advantage
is that the need for draping, positioning and sealing large vacuum bags over the cauls
is eliminated, thus reducing processing time and allowing increased production rates.
[0010] According to another aspect of the present disclosure, an apparatus for sealing a
caul over a composite part layup on a tool, comprising:
an edge seal extending around a perimeter of the caul and configured to form a vacuum
tight seal between the caul and the tool.
[0011] Advantageously, the apparatus is one wherein the edge seal is permanently attached
to the caul and is removably attached to the tool to allow the caul and the edge seal
to be removed together from the tool.
[0012] Preferably, the apparatus is one wherein the edge seal includes a strip of material
that overlaps the perimeter of the caul and a portion of the tool.
[0013] Preferably, the apparatus is one wherein the edge seal is adhesively bonded to the
caul.
[0014] Preferably, the apparatus is one wherein the edge seal includes a flexible membrane
configured to be formed over the caul and onto the tool.
[0015] Preferably, the apparatus further comprises a clamp configured to clamp the edge
seal to the tool.
[0016] According to another aspect of the present disclosure, an apparatus for sealing at
least first and second cauls over a composite barrel part layup up on a mandrel, comprising:
a first edge seal extending around a perimeter of the first caul and configured to
form a vacuum tight seal between the first caul and the mandrel; and
a second edge seal extending around a perimeter of the second caul and configured
to form a vacuum tight seal between the second caul and the mandrel,
wherein the first and second edge seals overlap and are configured to form a vacuum
tight seal between the first and second cauls.
[0017] Advantageously, the apparatus is one wherein the first edge seal is attached to the
first caul and includes a flap configured to be placed over and sealed to the second
edge seal.
[0018] Preferably, the apparatus is one wherein:
the first edge seal includes a longitudinally extending section and a circumferentially
extending section, and
the second edge seal includes a longitudinally extending section and a circumferentially
extending section,
wherein the circumferentially extending section of each of the first and second cauls
overlaps and is sealed to the mandrel.
[0019] Preferably, the apparatus is one wherein the first edge seal is configured to remain
attached to the first caul upon removal of the first caul from the composite barrel
part layup.
[0020] Preferably, the apparatus is one wherein the first edge seal includes a flap configured
to overlie the second edge seal.
[0021] Preferably, the apparatus includes a clamp configured to clamp and seal the flap
against the second edge seal.
[0022] Preferably, the apparatus is one wherein the clamp includes magnets on the flap configured
to be attracted to the mandrel and clamp the flap against the first edge seal.
[0023] Preferably, the apparatus is one wherein the clamp includes carbon fiber stiffeners
attached to and extending across the flap, the carbon fiber stiffeners being configured
to press the flap down into positive engagement with the second edge seal.
[0024] Preferably, the apparatus is one wherein the clamp comprises a plurality of collapsible
seals interposed between the flap and the second edge seal and configured to press
the flap down into positive engagement with the second edge seal.
[0025] According to another aspect of the present disclosure, a method of making at least
a section of a composite barrel, comprising:
forming a composite barrel part layup on a mandrel;
placing at least a first caul on the composite barrel part layup; and
forming a vacuum tight seal between the first caul and the mandrel, including sealing
a perimeter of the first caul to the mandrel.
[0026] Advantageously, the method is one wherein forming a vacuum tight seal includes sealing
a strip of elastomeric material around the perimeter of the first caul.
[0027] Preferably, the method further comprises placing at least a second caul on the composite
barrel layup;
forming a vacuum tight seal between the second caul and the mandrel, including sealing
a perimeter of the second caul to the mandrel; and
forming a vacuum tight seal between the first caul and the second caul, including
sealing a perimeter of the second caul to a perimeter of the first caul.
[0028] Preferably, the method is one wherein forming a vacuum tight seal between the first
caul and the second caul includes:
sealing an edge seal to a perimeter of first caul,
overlapping the edge seal over the perimeter of the second caul, and
sealing the edge seal to the second caul.
[0029] Preferably, the method is one wherein forming a vacuum tight seal includes:
integrating edge seals around the perimeters of each of the first and second cauls,
using the edge seals to form a vacuum tight seal between the first and second cauls,
and
using the edge seals to form a vacuum tight seal between the first and second cauls,
and the mandrel.
[0030] The features, functions, and advantages can be achieved independently in various
examples of the present disclosure or may be combined in yet other examples in which
further details can be seen with reference to the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The novel features believed characteristic of the illustrative examples are set forth
in the appended claims. The illustrative examples, however, as well as a preferred
mode of use, further objectives and advantages thereof, will best be understood by
reference to the following detailed description of an illustrative examples of the
present disclosure when read in conjunction with the accompanying drawings, wherein:
Figure 1 is an illustration of a perspective view of an aircraft.
Figure 2 is an illustration of a perspective view of a section of the fuselage of
the aircraft shown in Figure 1.
Figure 3 is an illustration of a perspective view of a half barrel part layup on a
mandrel, ready to be moved into an autoclave for curing.
Figure 4 is an illustration of a fragmentary, perspective view of a portion of the
part layup shown in Figure 3.
Figure 5 is an illustration of a sectional view taken along the line 5-5 in Figure
4.
Figure 5A is an illustration of the area designated as "FIG. 5A" in Figure 5.
Figure 5B is an illustration of the area designated as "FIG. 5B" in Figure 5.
Figure 5C is an illustration similar to Figure 4, but simplified and showing the location
of the breathers in broken lines.
Figure 6 is an illustration of a sectional view taken along the line 6-6 in Figure
4.
Figure 7 is an illustration of a sectional view similar to Figure 5, but showing an
alternate form of attachment of the edge seal to a caul.
Figure 8 is an illustration of a sectional view similar to Figure 6, but showing an
alternate form of attachment of the edge seal to a caul.
Figure 9 is an illustration of a sectional view showing a zipper forming part of the
alternate form of attachment shown in Figures 7 and 8.
Figure 10 is an illustration of a sectional view showing one form of sealing a flap
of the edge seal over an edge seal on an adjacent caul using magnets.
Figure 11 is an illustration of a sectional view showing a further form of sealing
the flap over an edge seal on an adjacent caul.
Figure 12 is an illustration of a sectional view showing another form of sealing the
flap over an edge seal on an adjacent caul.
Figure 13 is an illustration of a sectional view showing a further form of sealing
the flap over an edge seal on an adjacent caul.
Figure 14 is an illustration of a sectional view showing another form sealing the
flap over an edge seal on an adjacent caul.
Figure 15 is an illustration of a sectional view of one of the collapsible seals shown
in Figure 14, showing the seal in a collapsed condition.
Figure 16 is an illustration of a sectional view of a further form of sealing a flap
over and edge seal on an adjacent caul.
Figure 17 is an illustration of a perspective view showing one form of sealing a T-joint
in the edge seals.
Figure 18 is an illustration of a bottom plan view of a clamp shown in Figure 17.
Figure 19 is an illustration of a perspective view showing a further form of sealing
the T-joint in the edge seals.
Figure 20 is an illustration of a flow diagram of a method of making a section of
a composite barrel.
Figure 21 is an illustration of a flow diagram of aircraft production and service
methodology.
Figure 22 is an illustration of a block diagram of an aircraft.
DETAILED DESCRIPTION
[0032] Referring first to Figure 1, an aircraft 40 includes a fuselage 42, wings 44, horizontal
stabilizers 46, and a vertical stabilizer 48. In the illustrated example, the fuselage
42 is substantially cylindrical, however, in other examples the cross-sectional shape
of the fuselage 22 may have an oval or similar cross sectional shape. Referring also
to Figure 2, the fuselage 42 may comprise a plurality of barrel sections 49 joined
together end-to-end. Each of the barrel sections 49 comprises barrel halves 51 joined
together along a belt line 59, each of which comprises an outer skin 53 formed of
a composite laminate and reinforced by circumferentially extending, longitudinally
spaced frames 57, and longitudinally extending stringers 55. The outer skin 53, frames
57 and stringers 55 may each comprise a composite material, such as a carbon fiber
reinforced plastic (CFRP) laminate. In other examples, the barrel sections 49 may
be produced as a single cylindrical structure, rather than in two barrel halves 51.
[0033] Referring now to Figure 3, in one production example, each of the barrel halves 51
is produced by laying up composite material on a mandrel 52 that may be formed of
a metal and has a half barrel shape. Layup of the composite material may be performed
by automatic fiber placement machines (not shown) or similar robotic manipulators
that lay down layers of composite tape or split tape over the mandrel 52. Prior to
laying up the composite material on the mandrel 52, stringers 55 are placed in longitudinal
recesses (not shown) in the surface of the mandrel 52. With the stringers 55 having
first been installed on the mandrel 52, the outer skin 53 is then laid up on the mandrel
52 in direct contact with the stringers 55. The outer skin 53 and the stringers 55
are then cocured. For convenience of description, the outer skin laid up on the mandrel
52 will sometimes be referred to herein as a part layup 50.
[0034] Referring to Figures 3 and 4, following material layup, one or more cauls 60a, 60b
are placed on the part layup 50 in preparation for compacting and curing the part
layup 50 in an autoclave 58. The cauls 60a, 60b function to provide a desired profile
and/or surface roughness or finish on the OML (outer mold line) of the outer skin
53, while also applying even compaction pressure to the part layup 50 under autoclave
pressure. In the illustrated example, two cauls 60a, 60b are placed over the part
layup 50, however in other examples, a single, half barrel shaped caul (not shown)
may be placed over the part layup 50. As will be discussed below in greater detail,
the part layup 50 and the cauls 60a, 60b are not vacuum bagged in the usual manner,
but rather a vacuum tight seal is formed over the part layup 50 by sealing the cauls
60a, 60b to each other and to the mandrel 52 using edge seals 62a, 62b (discussed
later in connection with Figure 4) which are clamped together and to the mandrel 52.
The edges seals 62a, 62b effectively form localized sealing zones between the cauls
60a, 60b, as well as between the cauls 60a, 60 and the mandrel 52. The combination
of the cauls 60a, 60b and integrated edge seals 62a, 62b form a vacuum tight enclosure
over the part layup 50, thereby eliminating the need for a separate, all-encompassing
vacuum bag, and saving the time required to install a vacuum bag, while reducing consumables.
In some examples, the mandrel 52 may comprise a full barrel shape, rather than a half
barrel in which case cauls 60 are installed over the full barrel part layup and are
sealed to each other and to the mandrel 52. In fact, in some applications, depending
on the size and geometry of the part layup 50,
n number of cauls 60 (e.g. 4, 6 or 8) may be installed and sealed over the part layup
50. Moreover, the
n number of cauls 60 may be arranged side-by-side in the longitudinal direction 65
(Figure 4) as well as in the circumferential direction 67 of the part layup 50. As
used herein the term "caul" is used in its broadest sense and is defined as any type
of vacuum integral tooling that provides profile control and/or surface finish or
treatment of the OML of the part layup 50.
[0035] Attention is now directed to Figures 4, 5 and 6, which illustrate additional details
showing how the cauls 60a, 60b are sealed to each other and to the mandrel 52 in order
to form a vacuum tight enclosure over the part layup 50. The cauls 60a, 60b have IMLs
(inner mold lines) complementing the OML (outer mold line) of the barrel sections
49 and are separated by a gap 66, which allows them to expand relative to each other
when heated to processing temperatures. The cauls 60a, 60b, sometimes, referred to
herein as first and second cauls respectively, have edge seals 62a, 62b that overlie
and are attached to their entire outer perimeters. Thus, the edge seals 62a, 62b are
respectively integrated into the cauls 60a, 60b and remain attached to the cauls 60a,
60b upon removal of the cauls 60a, 60b from the part layup 50. Each of the edge seals
62a, 62b includes a longitudinal section 86 extending in a longitudinal direction
65 along the gap 66 between the two cauls 60a and 60b, and a circumferential section
88 extending in a circumferential direction 67 along the circumference of the mandrel
52. The longitudinal sections 86 and the circumferential sections 88 of the edge seals
62a, 62b intersect each other to form a T-junction 80. The edge seals 62a, 62b extend
over the top of vacuum ports 68 and pressure sensor ports 70 in the mandrel 52 which
are respectively used to draw and sense a vacuum beneath the cauls 60a, 60b to aid
in compaction of the part layup 50.
[0036] Each of the edge seals and 62a, 62b is a strip of material comprising a relatively
thin, flexible membrane-like elastomer, such as silicone rubber or .Viton
© that is sufficiently durable to permit repeated use. The ability to reuse the edge
seals 62a, 62b and the fact that they are permanently attached to the cauls 60a, 60b,
reduces installation labor costs as well as expendables. The elastomer selected is
capable of withstanding the temperatures and pressures normally used to compact and
cure fiber reinforced polymer materials, such as CFRP. The longitudinal section 86
of edge seals 62a includes a flap 64 that overlaps the longitudinal section 86 of
the adjacent edge seal 62b, and spans the gap 66 between the cauls 60a, 60b.
[0037] A filler 98 (Figure 5) formed from a suitable material such as an elastomer is placed
in the gap 66 to prevent undesired sagging of the flap 64 within the gap 66 during
autoclave processing, and to apply compaction pressure to the part layup 50 across
the gap 66. Use of the filler 98 results in even compaction pressure being applied
to the part layup 50 between the cauls 60a, 60b, despite the presence of the gap 66.
Figure 5A shows the filler 98 having been compressed by the flap 64 due to vacuum
and/or autoclave pressure, causing the filler 98 to deform, fill the gap 66, and apply
compaction pressure to the part layup 50 between the cauls 60a, 60b. A breather 90
is placed between the flap 64 and the underlying edge seal 62b to allow escape of
air and volatiles from the part layup 50, and to assist in spreading the vacuum applied
to the part layup 50 throughout the area beneath the cauls 60a, 60b.
[0038] In one example, shown in Figure 5B, a vacuum source (not shown) may be coupled to
the longitudinally extending edge seals 62a over the breathers 90 using a vacuum fitting
75 that is external. The vacuum source that is coupled with the vacuum fitting 75
may be any suitable vacuum generating device, including those normally used to evacuate
typical vacuum bags. The vacuum fitting 75 allows a vacuum to be applied through the
breather 90 to those areas beneath the edge seal 62a, or in other words, to those
areas that are not covered by the cauls 60. If desired, the vacuum fitting 75 may
be integrated into the edge seal 62a such that it remains attached to the edge seal
62a and thus may be reused when the cauls 60 are removed from the part layup 50. Referring
to Figure 5C, in another example, the breather 90 may extend longitudinally beyond
the outer edges of the cauls 60, onto the mandrel 52 so that it overlies one or more
of the vacuum ports 68 in the mandrel 52. In this example, air and volatiles are drawn
through the breather 90 into the vacuum ports 68 where vacuum is applied. As is also
shown in Figure 5C, the breather 90 may be extended longitudinally beyond the cauls
60 to intersect breather 92 at the T-junction, allowing a vacuum to be drawn beneath
both edge seals 62a, 62b through the vacuum ports 68 in the mandrel 52. The longitudinal
extension of the breather 90 in this manner allows a vacuum to be applied through
both of the breathers 90, 92 to those areas beneath the edge seal 62a, 62b that are
not covered by the cauls 60.
[0039] Referring to Figures 4 and 5, the inboard side 82 of the edge seal 62a is adhesively
attached around its entire perimeter to the underlying caul 60a along an adhesive
bond line 72. Likewise, edge seal 62b is adhesively attached around its entire perimeter
to the underlying caul 60b along an adhesive bond line 74. Other techniques for attaching
the edge seals 62a, 62b to the cauls 60a, 60b are possible.
[0040] Referring to Figures 4 and 6, the circumferential sections 88 of the edge seals 62a,
62b are draped down over the outer edges of the cauls 60a, 60b, and then down over
the cross sectional profile of the mandrel 52, including a ramp 96 along the outer
periphery 106 of the mandrel 52. Breather 92 and breather 94 are provided between
the circumferential sections 88 of the edge seals 62a, 62b, and the underlying mandrel
52, typically located above the vacuum ports 68 (Figure 4) to allow the escape of
the air, and volatiles during processing. In one example, breather 92 and breather
94 as well as breather 90 (Figure 5) may comprise individual pieces that are installed
separate from the edge seals 62a, 62b that cover them. However, in other examples,
breather 90, breather 92 and breather 94 may be integrated into the edge seals 62a,
62b, as by molding. As will be discussed below in more detail, the flap 64 is sealed
to the underlying longitudinal section of the edge seal 62b by any of a variety of
clamping techniques. Similarly, the circumferential sections 88 of both edge seals
62a, 52b are sealed to the mandrel 52 using any of a variety of clamping techniques.
[0041] In the example shown in Figures 4-6, the edge seals 62a, 62b are permanently attached
to the underlying cauls 60a, 60b by the adhesive bond lines 72, 74, allowing each
of the cauls 60 and their edge seals 62 to be removed together as an assembly. However
some applications it may be desirable to have the ability to easily remove the edge
seals 62a, 62b for any of various reasons. One technique for removably attaching the
edge seals 62a, 62b to the cauls 60a, 69b is illustrated in Figures 7, 8, and 9. In
this example, zippers 108 are employed to releasably attach the inner edges of the
edge seal 62a to the caul 60a. The zippers 108 each comprises a first toothed member
112 attached by a layer of adhesive 116 to the underlying caul 60a, and a second toothed
member 110 similarly attached to the edge seal 62a. Each of toothed member 110 and
toothed member 112, may be formed of any suitable material such as silicone. Toothed
member 110 and toothed member 112 friction fit together in interlocking relationship.
In some examples, it may be necessary or desirable to provide a filler ramp 114 along
an edge of the zipper 108 in order to smoothly ramp down the edge seal 62a from the
zipper 108 to the surface of the caul 60a. The use of a zipper 108 allows the edge
seal 62a to be easily removed when desired for cleaning, repair, and/or replacement.
Other techniques for releasably attaching the edge seal 62a to the caul 60a are possible.
In some examples, a zipper 108 may also be used to releasably attach either or both
of the edge seals 62a, 62b to a caul 60 that is adjacent or to the mandrel 52. For
example, in Figure 7 the flap 64 may be releasably attached and sealed to the caul
60b by a zipper 108 (not shown), and in Figures 8, the outer edge 104 (Figure 6) of
the edge seal 62a may be similarly releasably attached and sealed to the caul 60b
by a zipper 108.
[0042] A wide variety of techniques can be employed to releasably clamp or attach the flap
64 of edge seal 62a down over the edge seal 62b in order to form a vacuum tight seal
between these two edge seals 62a, 62b. These same clamping techniques can be used
to clamp and seal the longitudinal sections of the edge seals 62a, 62b to the mandrel
52. For example, referring to Figure 10, the outer end 84 of the flap 64 can be permanently
attached to a carbon fiber mounting strip 122 that is bonded by a layer of adhesive
124 to caul 60a. The outer end 84 of the flap 64 can be clamped to caul 60b by a series
of magnets 118 and/or ferromagnetic materials that are placed on top of or embedded
into the flap 64. The magnets 118 are attracted to the mandrel 52 or to ferromagnetic
materials (not shown) embedded in the mandrel 52, thereby clapping the flap 64 down
against the caul 60b. In some applications, it may also be possible to attach the
edge seal 62a to the caul 60a using magnets 118 in lieu of the use of an adhesive.
[0043] Figure 11 illustrates another form of clamping devices in which spring members 130
such as carbon fiber stiffeners are bonded to the outer end 84 of the flap 64. It
may be possible to fabricate the spring member 130 from materials other than carbon
fiber, such as spring steel. The spring member 130 has a preformed curved shape that
causes the outer extremities 64a of the flap 64 to be forced down onto positive engagement
and seal against the caul 60b.
[0044] Figure 12 illustrates another technique for sealing the flap 64 against the caul
60b. In this example, a strip 132 of flexible spring material, such as a metal or
carbon fiber is attached by adhesive 134 to the caul 60b. The strip 132 forces a pressure
concentrator 136 such as a rod-like member which forces the outer end 84 of the flap
64 to seal against the edge seal 62b.
[0045] A further example of sealing the flap 64 against the caul 60b is shown in Figure
13. In this example, the outer end 84 of the flap 64 includes a stiffener 142 secured
by a layer of adhesive 144 to a flexible seal 146 having the cross sectional shape
of an inverted "7". An inflatable hose 140 is positioned between the top of the flap
64, and a strongback 138 which may comprise, for example and without limitation, a
rigid frame. Inflation of the hose 140 forces the flap 64 downwardly, causing the
flexible seal 146 to collapse and form a vacuum tight seal between the flap 64 and
the edge seal 62b. Alternatively, the strongback 138 may be displaced downwardly,
causing a preinflated hose 140 to force the flexible seal 146 to collapse.
[0046] Referring to Figures 14 and 15, in another example, a pair of the flexible seals
146 are positioned at spaced apart locations between the flap 64 and the edge seal
62b. In this example, the flexible seals 146 are subjected to a vacuum and act as
vacuum chucks which draw down the flap 64, causing the flexible seals 146 to collapse
(see Figure 15) against the edge seal 62b, creating a vacuum tight seal between the
edge seals 62a and 62b.
[0047] Attention is now directed to Figure 16, which illustrates another example of a technique
for sealing the flap 64 against the edge seal 62b. In this example, rather than overlapping
the flap 64 over the edge seal 62b, the outer end 84 of the flap 64 and the inner
end 100 of the edge seal 62b are arranged in face-to-face relationship and are seal
together with magnets 148 or other means, such as a clamp (not shown) . A spacer 170
may be placed between the ends of the flap 64 and the edge seal 62b to maintain their
face-to-face orientation.
[0048] Referring to Figure 17 and 18, the longitudinal section 86 and the circumferential
section 88 of the edge seals 62a, 62b intersect at a T-junction 80 as previously mentioned.
In order to assure that there is no air leakage at the T-junction 80, a clamp 172
may be provided to force the two edge seal 62a, 62b together against the mandrel 52
at the T-junction. The clamp 172 may comprise any of a number of mechanisms, but in
the illustrated example, comprises a toggle mechanism 164. The toggle mechanism includes
a base 160 mounted on the mandrel 52 and a pressure plate 158. The bottom of the pressure
plate 158 includes a rectangular, gasket-like seal 162. The toggle mechanism 164 forces
the pressure plate 158 downwardly, causing the gasket-like seal 162 to apply pressure
at the T-junction 80, thereby creating a tight seal at this location between the edge
seals 62a and 62b.
[0049] Figure 19 illustrates another example of a technique for assuring that air leaks
do not occur at the T-junction 80. In this example, a vacuum bag 166 is placed over
the area of the T-junction and sealed to the underlying edge seals 62a, 62b by a bead
of sealant 168.
[0050] Attention is now directed to Figure 20, which broadly illustrates the steps of a
method of making at least a section of a composite barrel using cauls 60 having the
edge seals 62 described above. Beginning at 171, a composite barrel layup is formed
on a mandrel 52. At 174, at least a first caul 60a is placed on the composite barrel
layup. At 176, a vacuum tight seal is formed between the first caul 60a and the mandrel
52, thereby creating a local sealing zone. The seal at 176 may be formed by sealing
the perimeter of the caul to the mandrel 52, as by sealing a strip of elastomeric
material to the caul. Although not shown in Figure 20, as previously described, cauls
60 may be installed on the composite barrel layup and sealed to the mandrel 52 and
to each other using edge seals 62 that create localized sealing zones.
[0051] Examples of the disclosure may find use in a variety of potential applications, particularly
in the transportation industry, including for example, aerospace, marine, and other
applications where vacuum bag compaction of composite part layups utilize cauls. Thus,
referring now to Figures 21 and 22, examples of the disclosure may be used in the
context of an aircraft manufacturing and service method 182 as shown in Figure 21
and an aircraft 184 as shown in Figure 22. Aircraft applications of the disclosed
examples may include a variety of composite parts and structures, including sections
of a fuselage 201. During pre-production, exemplary manufacturing and service method
182 may include specification and design 186 of the aircraft 184 and material procurement
188. During production, component and subassembly manufacturing 190 and system integration
192 of the aircraft takes place. Thereafter, the aircraft 184 may go through certification
and delivery 194 in order to be placed in service 196. While in service by a customer,
the aircraft 184 is scheduled for routine maintenance and service 198, which may also
include modification, reconfiguration, refurbishment, and so on. The disclosed embodiments
may be used in one or more of production process 190 or production process, or in
the airframe 200 or in the fuselage 201.
[0052] Each of the processes of manufacturing and service method 182 may be performed or
carried out by a system integrator, a third party, and/or an operator (e.g., a customer).
For the purposes of this description, a system integrator may include without limitation
any number of aircraft manufacturers and major-system subcontractors; a third party
may include without limitation any number of vendors, subcontractors, and suppliers;
and an operator may be an airline, leasing company, military entity, service organization,
and so on.
[0053] As shown in Figure 22, the aircraft 184 produced by exemplary manufacturing and service
method 182 may include an airframe 200 having a fuselage 201, a plurality of high
level systems 202 and an interior 204. Examples of high-level systems 202 include
one or more of a propulsion system 206, an electrical system 208, a hydraulic system
210 and an environmental system 212. Any number of other systems may be included.
Although an aerospace example is shown, the principles of the disclosure may be applied
to other industries, such as the marine and automotive industries.
[0054] Systems and methods embodied herein may be employed during any one or more of the
stages of the manufacturing and service method 182. For example, components or subassemblies
corresponding to production process 190 may be fabricated or manufactured in a manner
similar to components or subassemblies produced while the aircraft 184 is in service.
Also, one or more apparatus examples, method examples, or a combination thereof may
be utilized during production process 190 and production process 192, for example,
by substantially expediting assembly of or reducing the cost of an aircraft 184. Similarly,
one or more of apparatus examples, method examples, or a combination thereof may be
utilized while the aircraft 184 is in service, for example and without limitation,
to maintenance and service 198.
1. An apparatus for sealing at least first and second cauls (60a, 60b) over a composite
barrel part layup (50) on a mandrel (52), comprising:
a first edge seal (62a) extending around a perimeter (76) of the first caul (60a)
and configured to form a vacuum tight seal between the first caul (60a) and the mandrel
(52); and
a second edge seal (62b) extending around a perimeter (76) of the second caul (60b)
and configured to form a vacuum tight seal between the second caul (60b) and the mandrel
(52),
wherein the first and second edge seals (62a, 62b) overlap and are configured to form
a vacuum tight seal between the first and second cauls (60a, 60b).
2. The apparatus of claim 1, wherein the first edge seal (62a) is attached to the first
caul (60a) and includes a flap (64) configured to be placed over and sealed to the
second edge seal (62b) .
3. The apparatus according to Claimslor2, wherein:
the first edge seal (62a) includes a longitudinally extending section (86) and a circumferentially
extending section (88), and
the second edge seal (62b) includes a longitudinally extending section (86) and a
circumferentially extending section (88),
wherein the circumferentially extending section (88) of each of the first and second
cauls (60a, 60b) overlaps and is sealed to the mandrel (52).
4. The apparatus according to any of claims 1 to 3, wherein the first edge seal (62a)
is configured to remain attached to the first caul (60a) upon removal of the first
caul (60a) from the composite barrel part layup (50).
5. The apparatus according to any of claims 1 to 4, wherein the first edge seal (62a)
includes a flap (64) configured to overlie the second edge seal (62b).
6. The apparatus of claim 5, including a clamp (118, 130, 132) configured to clamp and
seal the flap (64) against the second edge seal (62b).
7. The apparatus of claim 6, wherein the clamp includes magnets (118) on the flap (64)
configured to be attracted to the mandrel (52) and clamp the flap (64) against the
first edge seal (62a).
8. The apparatus according to Claims 6 or 7, wherein the clamp includes carbon fiber
stiffeners (130) attached to and extending across the flap (64), the carbon fiber
stiffeners (130) being configured to press the flap (64) down into positive engagement
with the second edge seal (62b).
9. The apparatus according to any of claims 6 to 8, wherein the clamp comprises a plurality
of collapsible seals (146) interposed between the flap (64) and the second edge seal
(62b) and configured to press the flap (64) down into positive engagement with the
second edge seal (62b).
10. The apparatus according to any of claims 1 to 9, wherein an edge seal (62) extending
around a perimeter (76) of the caul (60) and configured to form a vacuum tight seal
between the caul (60) and the tool (52).
11. A method of making at least a section (49) of a composite barrel, comprising:
forming a composite barrel part layup (50) on a mandrel (52);
placing at least a first caul (60a) on the composite barrel part layup (50); and
forming a vacuum tight seal between the first caul (60a) and the mandrel (52), including
sealing a perimeter of the first caul (60a) to the mandrel (52) further comprising:
placing at least a second caul (60b) on the composite barrel part layup (50);
forming a vacuum tight seal between the second caul (60b) and the mandrel (52), including
sealing a perimeter (76) of the second caul (60b) to the mandrel (52); and
forming a vacuum tight seal between the first caul (60a) and the second caul (60b),
including sealing a perimeter (76) of the second caul (60b) to a perimeter (76) of
the first caul (60a),
wherein forming a vacuum tight seal between the first caul (60a) and the second caul
(60b) includes:
sealing an edge seal (62a) to a perimeter (76) of first caul (60a),
overlapping the edge seal (62a) over the perimeter (76) of the second caul (60b),
and
sealing the edge seal (62a) to the second caul (60b).
12. The method of claim 11, wherein forming a vacuum tight seal includes sealing a strip
(62a) of elastomeric material around the perimeter (76) of the first caul (60a).
13. The method according to Claim 11 or 12, wherein forming a vacuum tight seal includes:
integrating edge seals (62a, 62b) around the perimeters (76) of each of the first
and second cauls (60a, 60b);
using the edge seals (62a, 62b) to form a vacuum tight seal between the first and
second cauls (60a, 60b); and
using the edge seals (62a, 62b) to form a vacuum tight seal between the first and
second cauls (62a, 62b), and the mandrel (52) .
14. Use of an apparatus according to any of the claims 1-10, in a method according to
any of the claims 11-13.
15. Use of an apparatus according to any of the claims 1-10, or 14 in making an aircraft
part.
1. Vorrichtung zum Abdichten von mindestens einer ersten und einer zweiten Umhüllung
(60a, 60b) über einer Verbundtrommelteilelaminierung (50) auf einem Dorn (52), umfassend:
eine erste Randabdichtung (62a), die sich um einen Umfang (76) der ersten Umhüllung
(60a) herum erstreckt und konfiguriert ist, um eine vakuumdichte Abdichtung zwischen
der ersten Umhüllung (60a) und dem Dorn (52) auszubilden; und
eine zweite Randabdichtung (62b), die sich um einen Umfang (76) der zweiten Umhüllung
(60b) herum erstreckt und konfiguriert ist, um eine vakuumdichte Abdichtung zwischen
der zweiten Umhüllung (60b) und dem Dorn (52) auszubilden,
wobei die erste und die zweite Randabdichtung (62a, 62b) überlappen und konfiguriert
sind, um eine vakuumdichte Abdichtung zwischen der ersten und der zweiten Umhüllung
(60a, 60b) auszubilden.
2. Vorrichtung nach Anspruch 1, wobei die erste Randabdichtung (62a) an der ersten Umhüllung
(60a) befestigt ist und eine Klappe (64) einschließt, die konfiguriert ist, um über
die zweite Randabdichtung (62b) gelegt und mit dieser abgedichtet zu werden.
3. Vorrichtung nach Anspruch 1 oder 2, wobei:
die erste Randabdichtung (62a) einen sich in Längsrichtung erstreckenden Abschnitt
(86) und einen sich in Umfangsrichtung erstreckenden Abschnitt (88) einschließt, und
die zweite Randabdichtung (62b) einen sich in Längsrichtung erstreckenden Abschnitt
(86) und einen sich in Umfangsrichtung erstreckenden Abschnitt (88) einschließt,
wobei der sich in Umfangsrichtung erstreckende Abschnitt (88) jeweils der ersten und
der zweiten Umhüllung (60a, 60b) den Dorn (52) überlappt und mit diesem abgedichtet
ist.
4. Vorrichtung nach einem der Ansprüche 1 bis 3, wobei die erste Randabdichtung (62a)
konfiguriert ist, um nach einem Entfernen der ersten Umhüllung (60a) von der Verbundtrommelteilelaminierung
(50) an der ersten Dichtung (60a) befestigt zu bleiben.
5. Vorrichtung nach einem der Ansprüche 1 bis 4, wobei die erste Randabdichtung (62a)
eine Klappe (64) einschließt, die konfiguriert ist, um über der zweiten Randabdichtung
(62b) zu liegen.
6. Vorrichtung nach Anspruch 5, einschließlich einer Klemme (118, 130, 132), die konfiguriert
ist, um die Klappe (64) gegen die zweite Randabdichtung (62b) zu klemmen und abzudichten.
7. Vorrichtung nach Anspruch 6, wobei die Klemme Magnete (118) an der Klappe (64) einschließt,
die konfiguriert sind, um zu dem Dorn (52) gezogen zu werden und die Klappe (64) gegen
die erste Randabdichtung (62a) klemmen.
8. Vorrichtung nach Anspruch 6 oder 7, wobei die Klemme Kohlefaserversteifungsglieder
(130) einschließt, die an der Klappe (64) befestigt sind und sich über diese hinweg
erstrecken, wobei die Kohlefaserversteifungsglieder (130) konfiguriert sind, um die
Klappe (64) nach unten in einen Formschluss mit der zweiten Randabdichtung (62b) zu
drücken.
9. Vorrichtung nach einem der Ansprüche 6 bis 8, wobei die Klemme eine Vielzahl faltbarer
Abdichtungen (146) umfasst, die zwischen der Klappe (64) und der zweiten Randabdichtung
(62b) angeordnet sind und konfiguriert sind, um die Klappe (64) nach unten in den
Formschluss mit der zweiten Randabdichtung (62b) zu drücken.
10. Vorrichtung nach einem der Ansprüche 1 bis 9, wobei sich eine Randabdichtung (62)
um einen Umfang (76) der Umhüllung (60) herum erstreckt und konfiguriert ist, um eine
vakuumdichte Abdichtung zwischen der Umhüllung (60) und dem Werkzeug (52) auszubilden.
11. Verfahren zum Herstellen von mindestens einem Abschnitt (49) einer Verbundtrommel,
umfassend:
Ausbilden einer Verbundtrommelteilelaminierung (50) auf einem Dorn (52);
Legen von mindestens einer ersten Umhüllung (60a) auf die Verbundtrommelteilelaminierung
(50); und
Ausbilden einer vakuumdichten Abdichtung zwischen der ersten Umhüllung (60a) und dem
Dorn (52), einschließlich des Abdichtens eines Umfangs der ersten Dichtung (60a) mit
dem Dorn (52), ferner umfassend:
Legen von mindestens einer zweiten Umhüllung (60b) auf die Verbundtrommelteilelaminierung
(50);
Ausbilden einer vakuumdichten Abdichtung zwischen der zweiten Umhüllung (60b) und
dem Dorn (52), einschließlich des Abdichtens eines Umfangs (76) der zweiten Umhüllung
(60b) mit dem Dorn (52); und
Ausbilden einer vakuumdichten Abdichtung zwischen der ersten Umhüllung (60a) und der
zweiten Umhüllung (60b), einschließlich des Abdichtens eines Umfangs (76) der zweiten
Umhüllung (60b) mit einem Umfang (76) der ersten Dichtung (60a),
wobei das Ausbilden einer vakuumdichten Abdichtung zwischen der ersten Dichtung (60a)
und der zweiten Dichtung (60b) einschließt:
Abdichten einer Randabdichtung (62a) an einem Umfang (76) der ersten Umhüllung (60a),
Überlappen der Randabdichtung (62a) über den Umfang (76) der zweiten Umhüllung (60b)
und
Abdichten der Randabdichtung (62a) an der zweiten Umhüllung (60b).
12. Verfahren nach Anspruch 11, wobei das Ausbilden einer vakuumdichten Abdichtung das
Abdichten eines Streifens (62a) aus Elastomermaterial um den Umfang (76) der ersten
Umhüllung (60a) herum einschließt.
13. Verfahren nach Anspruch 11 oder 12, wobei das Ausbilden einer vakuumdichten Abdichtung
einschließt:
Integrieren von Randabdichtungen (62a, 62b) um die Umfänge (76) jeder der ersten und
der zweiten Umhüllung (60a, 60b) herum;
Verwenden der Randabdichtungen (62a, 62b), um eine vakuumdichte Abdichtung zwischen
der ersten und der zweiten Umhüllung (60a, 60b) auszubilden; und
Verwenden der Randabdichtungen (62a, 62b), um eine vakuumdichte Abdichtung zwischen
der ersten und der zweiten Umhüllung (62a, 62b) und dem Dorn (52) auszubilden.
14. Verwendung einer Vorrichtung nach einem der Ansprüche 1 bis 10 in einem Verfahren
nach einem der Ansprüche 11 bis 13.
15. Verwendung einer Vorrichtung nach einem der Ansprüche 1 bis 10 oder 14 bei dem Herstellen
eines Flugzeugteils.
1. Appareil destiné à sceller au moins des première et seconde plaques de presse (60a,
60b) sur un assemblage de cylindre composite (50) sur un mandrin (52), comprenant
:
un premier joint de bord (62a) s'étendant autour d'un périmètre (76) de la première
plaque de presse (60a) et conçu pour former un joint étanche au vide entre la première
plaque de presse (60a) et le mandrin (52) ; et
un second joint de bord (62b) s'étendant autour d'un périmètre (76) de la seconde
plaque de presse (60b) et conçu pour former un joint étanche au vide entre la seconde
plaque de presse (60b) et le mandrin (52),
dans lequel les premier et second joints de bord (62a, 62b) se chevauchent et sont
conçus pour former un joint étanche au vide entre les première et seconde plaques
de presse (60a, 60b).
2. Appareil selon la revendication 1, dans lequel le premier joint de bord (62a) est
fixé à la première plaque de presse (60a) et comprend un rabat (64) conçu pour être
placé sur le second joint de bord (62b) et scellé à celui-ci.
3. Appareil selon la revendication 1 ou 2, dans lequel :
le premier joint de bord (62a) comporte une coupe s'étendant longitudinalement (86)
et une coupe s'étendant sur la circonférence (88), et
le second joint de bord (62b) comporte une coupe s'étendant longitudinalement (86)
et une coupe s'étendant sur la circonférence (88),
dans lequel la coupe s'étendant sur la circonférence (88) de chacune des première
et seconde plaques de presse (60a, 60b) se chevauche et est scellée au mandrin (52).
4. Appareil selon l'une quelconque des revendications 1 à 3, dans lequel le premier joint
de bord (62a) est conçu pour rester attaché à la première plaque de presse (60a) lors
du retrait de la première plaque de presse (60a) de l'assemblage de cylindre composite
(50).
5. Appareil selon l'une quelconque des revendications 1 à 4, dans lequel le premier joint
de bord (62a) comporte un rabat (64) conçu pour recouvrir le second joint de bord
(62b).
6. Appareil selon la revendication 5, comprenant une pince (118, 130, 132) conçue pour
serrer et sceller le rabat (64) contre le second joint de bord (62b).
7. Appareil selon la revendication 6, dans lequel la pince comporte des aimants (118)
sur le rabat (64) conçus pour être attirés par le mandrin (52) et serrer le rabat
(64) contre le premier joint de bord (62a).
8. Appareil selon les revendications 6 ou 7, dans lequel la pince comporte des raidisseurs
en fibre de carbone (130) fixés au rabat (64) et s'étendant à travers celui-ci, les
raidisseurs en fibre de carbone (130) étant conçus pour presser le rabat (64) vers
le bas dans une mise en prise positive avec le second joint de bord (62b).
9. Appareil selon l'une quelconque des revendications 6 à 8, dans lequel la pince comprend
une pluralité de joints pliables (146) interposés entre le rabat (64) et le second
joint de bord (62b) et conçus pour presser le rabat (64) vers le bas dans une mise
en prise positive avec le second joint de bord (62b).
10. Appareil selon l'une quelconque des revendications 1 à 9, dans lequel un joint de
bord (62) s'étendant autour d'un périmètre (76) de la plaque de presse (60) et conçu
pour former un joint étanche au vide entre la plaque de presse (60) et l'outil (52).
11. Procédé de fabrication d'au moins une coupe (49) d'un cylindre composite, comprenant
:
la formation d'un assemblage de cylindre composite (50) sur un mandrin (52) ;
le placement d'au moins une première plaque de presse (60a) sur l'assemblage de cylindre
composite (50) ; et
la formation d'un joint étanche au vide entre la première plaque de presse (60a) et
le mandrin (52), y compris le scellement d'un périmètre de la première plaque de presse
(60a) au mandrin (52), comprenant en outre :
le placement d'au moins une seconde plaque de presse (60b) sur l'assemblage de cylindre
composite (50) ;
la formation d'un joint étanche au vide entre la seconde plaque de presse (60b) et
le mandrin (52), y compris le scellement d'un périmètre (76) de la seconde plaque
de presse (60b) au mandrin (52) ; et
la formation d'un joint étanche au vide entre la première plaque de presse (60a) et
la seconde plaque de presse (60b), y compris le scellement d'un périmètre (76) de
la seconde plaque de presse (60b) à un périmètre (76) de la première plaque de presse
(60a),
dans lequel la formation d'un joint étanche au vide entre la première plaque de presse
(60a) et la seconde plaque de presse (60b) comporte :
le scellement d'un joint de bord (62a) sur un périmètre (76) de la première plaque
de presse (60a),
le chevauchement du joint de bord (62a) sur le périmètre (76) de la seconde plaque
de presse (60b), et
le scellement du joint de bord (62a) à la seconde plaque de presse (60b).
12. Procédé selon la revendication 11, dans lequel la formation d'un joint étanche au
vide comprend le scellement d'une bande (62a) de matériau élastomère autour du périmètre
(76) de la première plaque de presse (60a).
13. Procédé selon la revendication 11 ou 12, dans lequel la formation d'un joint étanche
au vide comporte :
l'intégration des joints de bord (62a, 62b) autour des périmètres (76) de chacune
des première et seconde plaques de presse (60a, 60b) ;
l'utilisation des joints de bord (62a, 62b) pour former un joint étanche au vide entre
les première et seconde plaques de presse (60a, 60b) ; et
l'utilisation des joints de bord (62a, 62b) pour former un joint étanche au vide entre
les première et seconde plaques de presse (62a,62b), et le mandrin (52).
14. Utilisation d'un appareil selon l'une quelconque des revendications 1 à 10, dans un
procédé selon l'une quelconque des revendications 11 à 13.
15. Utilisation d'un appareil selon l'une quelconque des revendications 1 à 10, ou 14
pour la fabrication d'une pièce d'avion.